Multi-vector sensing in cardiac devices with detection combinations

• US 10,362,948 B2
• Filed: 10/19/2016
• Issued: 07/30/2019
• Est. Priority Date: 10/23/2015
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Brisben, Amy Jean, Allavatam, Venugopal, Mahajan, Deepa, Siejko, Krzysztof Z., Wika, Kevin G., Herrmann, Keith L., Hahn, Stephen J.
• Primary Examiner(s): Porter, Allen
• Application Number:
  US15/297,605
• Publication Number:
  US 20170113050A1
• Time in Patent Office: 1,014 Days
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/327 Generation of artificial ECG signals based on measured signals, e.g. to compensate for missing leads
• CPC Class Codes: A61B 5/341 Vectorcardiography [VCG]
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/35 by template matching
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/364 Detecting abnormal ECG interval, e.g. extrasystoles, ectopic heartbeats
• CPC Class Codes: A61B 5/366 Detecting abnormal QRS complex, e.g. widening
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/6869 Heart
• CPC Class Codes: A61B 5/72 Signal processing specially adapted for physiological signals or for diagnostic purposes character recognition, recognising digital ink, document-oriented image-based pattern recognition G06V30/00; recognition or understanding of postal images G06V30/424
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61N 1/046 Specially adapted for shock therapy, e.g. defibrillation
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/0563 : specially adapted for defibrillation or cardioversion
• CPC Class Codes: A61N 1/3622 : comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3625 : External stimulators
• CPC Class Codes: A61N 1/36514 : controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/3704 : Circuits specially adapted therefor, e.g. for sensitivity control
• CPC Class Codes: A61N 1/3925 : Monitoring; Protecting
• CPC Class Codes: A61N 1/3956 : Implantable devices for applying electric shocks to the heart, e.g. for cardioversion
• CPC Class Codes: A61N 1/3987 : characterised by the timing or triggering of the shock

Abstract

Methods and devices for combining multiple signals from multiple sensing vectors for use in wearable or implantable cardiac devices. Signals from multiple vectors may be combined using weighting factors and/or by conversion to different coordinate systems than the original inputs, which may or may not be normalized to patient anatomy. Signals from multiple sensing vectors may be combined prior to or after several analytical steps or processes including before or after filtering, and before or after cardiac cycle detection. Cardiac cycle detection information may be combined across multiple sensing vectors before or after analysis of individual vectors for noise or overdetection. Cardiac cycle detection information may also be combined across multiple sensing vectors to identify noise and/or overdetection.

Claims

1. A cardiac rhythm management device comprising at least first and second input nodes to define a least a first sensing vector and operational circuitry for analyzing cardiac signals on at least two data streams, the operational circuitry being configured to:

receive a signal from the first sensing vector;

in a first data stream, apply a first filtering criteria to the signal from the first sensing vector;

in a second data stream, apply a second filtering criteria different from the first filtering criteria applied to the signal from the first sensing vector;

combine the first and second data streams together to create a series of combined sample points for the cardiac signal each having an amplitude determined at least partly from each of the first and second data streams;

detect cardiac events in the series of combined sample points; and

calculate a cardiac rate using the detected cardiac events.

2. The device of claim 1 wherein the operational circuitry is configured to correct for phase differences in the first and second data stream prior to or as part of combining the first and second data streams together.

3. The device of claim 1 wherein each of the combined sample points is generated by adding data from the first data stream to data from the second data stream.

4. The device of claim 1 wherein each of the combined sample points is generated by adding weighted data from the first data stream to weighted data from the second data stream.

5. The device of claim 1 wherein the combined sample points are combined together by addition during a first time period, and by subtraction during a second time period, of a cardiac cycle.

6. An implantable cardiac therapy system comprising the cardiac rhythm management device of claim 1 and implantable electrodes for coupling to the first and second electrical input nodes, wherein the cardiac rhythm management device further includes output circuitry configured to deliver therapy in response to identification of a treatable condition, such identification based at least in part on the cardiac rate, by the operational circuitry and an implantable canister containing the operational circuitry and the output circuitry.

7. A wearable cardiac defibrillator comprising the cardiac rhythm management device of claim 1, a plurality of cutaneous electrodes for coupling to the first and second electrical input nodes, and output circuitry configured to deliver therapy in response to identification of a treatable condition, such identification based at least in part on the cardiac rate, by the operational circuitry.

8. An implantable cardiac monitoring device comprising the cardiac rhythm management device of claim 1, a memory, and an implantable canister containing the memory and the operational circuitry, wherein the operational circuity is further configured to:

determine whether to record data from the first and second data streams by analysis of the cardiac rate; and

recording the data in the memory in response to determining to record the data.

9. A wearable cardiac monitoring device comprising the cardiac rhythm management device of claim 1, a memory, and one or more cutaneous electrodes coupled to the first and second inputs, wherein the operational circuity is further configured to:

determine whether to record data from the first and second data streams by analysis of the cardiac rate; and

record the data in the memory in response to determining to record the data.

10. A method of operation in a cardiac rhythm management device, the device having at least first and second input nodes to define a least a first sensing vector and operational circuitry for analyzing cardiac signals on at least two data streams, the method comprising the operational circuitry doing each of the following:

receiving a signal from the first sensing vector;

in a first data stream, applying a first filtering criteria to the signal from the first sensing vector;

in a second data stream, applying a second filtering criteria different from the first filtering criteria to the signal from the first sensing vector;

combining the first and second data streams together to create a series of combined sample points for the cardiac signal each having an amplitude determined at least partly from each of the first and second data streams;

detecting cardiac cycles using the series of combined sample points; and

calculating a cardiac rate using detected cardiac cycles.

11. The method of claim 10 further comprising the operational circuitry correcting for phase differences in the first and second data stream prior to or as part of combining the first and second data streams together.

12. The method of claim 10 wherein each of the combined sample points is generated by adding data from the first data stream to data from the second data stream.

13. The method of claim 10 wherein each of the combined sample points is generated by adding weighted data from the first data stream to weighted data from the second data stream.

14. The method of claim 10 wherein the combined sample points are combined together by addition during a first time period, and by subtraction during a second time period, of a cardiac cycle.

15. The method of claim 10 wherein the cardiac rhythm management device is an implantable cardiac therapy system comprising implantable electrodes for coupling to the first and second electrical input nodes, output circuitry configured to deliver therapy in response to identification of a treatable condition by the operational circuitry, and a canister housing at least the operational circuitry and output circuitry, the method further comprising the operational circuitry identifying the treatable condition using at least the cardiac rate and delivering the therapy using the output circuitry in response to the treatable condition.

16. The method of claim 10 wherein the cardiac rhythm management device is a wearable defibrillator comprising cutaneous electrodes for coupling to the first and second electrical input nodes and the step of receiving a signal from the first sensing vector comprises receiving a signal from the cutaneous electrodes and output circuitry configured to deliver therapy in response to identification of a treatable condition by the operational circuitry, the method further comprising the operational circuitry identifying the treatable condition using the cardiac rate and delivering the therapy via the output circuitry in response to the treatable condition.

17. The method of claim 10 wherein the cardiac rhythm management device is an implantable monitoring device having a memory and an implantable canister containing the operational circuitry and the memory, and the method further includes the operational circuity doing each of the following:

determine whether to record data from the first and second data streams using the cardiac rate; and

recording the data in the memory in response to determining to record the data.

18. The method of claim 10 wherein the cardiac rhythm management device is a wearable monitoring device having a memory and the method further includes the operational circuity doing each of the following:

determine whether to record data from the first and second data streams using the detected rate; and

recording the data in the memory in response to determining to record the data.